The sudo command allows for a high degree of flexibility. For instance, only users listed in the /etc/sudoers configuration file are allowed to use the sudo command and the command is executed in the user's shell, not a root shell. This means the root shell can be completely disabled as shown in the Red Hat Enterprise Linux 6 Security Guide.
By uncommenting the sudo group line in /etc/sudoers, you can add all users that need to have sudo access to the sudo group. This may or may not be easier to do than adding a new file in sudoers.d, depending on your setup. However, changing the shipped configuration file may make things harder (e.g., if there is an update of your distribution sudo install, usage and sudoers config file basics Aug 20, 2018 Understanding the /etc/sudoers file | LinuxG.net The /etc/sudoers file is the configuration files for sudo. These is the file where the users and groups with root priviledges are stored. Do not edit the /etc/sudoers by hand, use sudo visudo instead. visudo opens the /etc/sudoers file in the default text editor and gives a warning if you type something wrong in the file:
How to Configure "SUDO" access for users in Linux
Sudo Command in Linux - Baeldung on Linux
May 04, 2020
Nov 04, 2019 How to Fix "Username is not in the sudoers file. This Nov 15, 2016 How to enable sudo on Red Hat Enterprise Linux - Red Hat